The objectives of this project are to describe the pharmacological, biochemical and morphological changes that occur in saphenous veins following grafting into the femoral artery or to its original in situ location. Experiments to date indicate that within one week, the trauma of surgery (in situ graft) results in a reduction in maximum contractile force, denervation and an increase in adrenergic neurotransmitter sensitivity. The reduction in maximum force can be accounted for by a reduction in actomyosin. After one month, the contractile function and actomyosin content have returned to normal; however, the sensitivity to neurotransmitter remains elevated. If the grafted vessel is also subjected to the effects of elevated pressure/flow (femoral graft) therefore is a greater loss of contractile function which can not be attributed to a loss of actomyosin and the recovery of contractile function does not occur within one month. In the subsequent year, the effect of longer grafting time on the recovery of contractile function will be examined, as well as the effect of grafting into the coronary bed.